SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2a62da6a56d61f639975c89f4eaca47818673c3e5ed48270e53917b30b00734' 
  AND token = 'z3AFOqRyO1VpXbvVINP9hOtbg1wHM9YKWJnLDIE463s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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