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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9eb91d96b6a566c2382f90a3e2fa46762d0fd8e0e1809f00e5aa426aaa486651' 
  AND token = 'btyit3Gzcg+Fuu2O+TqflUHzDdQ8KjQ0ox5uQcUYXxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}