SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3451f4c90b02cf9bf57b4ece4b4cd1bafac2066c975d1139ebf509410546cd13' 
  AND token = '3NqEI/C4wIZtsnNPgBtFS1iqOV8WWWFPKxLEDGhKW6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}