SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b34137452c081f619a9a8ba1b0b09891cdc19c9b992e9cefe6c4bbb6f465c529' 
  AND token = '5U6YH19daG8Sf+9AR/ooaubIt9F5xSQCG1Sd0yVjMpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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