SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c653de45578e5f241ec32835d1286d48de8504023ca10a7140746366c26e90b1' 
  AND token = 'dOpqdd3t9naYHuh1JYSg2qpAfE1XFikfGBGn7IkGMxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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