SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5a3fa8e631d731eebad59e0b2f6e9422b1da2e8c592dacd93a135532184d175' 
  AND token = 'kcNH90qoum+i57hUrYR4AFVjp/83yWQSNuSm9qNiBow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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