SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce6715a353e565efaa2148adbf08b87e6b3573174c46cefe6a04b3c6c5f6a4de' 
  AND token = 'oSLnnaB5B3OLDHRu06r+LQG74ZGYHURCsIfo+uD6YYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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