SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a85aded038df1f6d725dd9a1010acc9c36be0bb33ec427ec97c01ab4bfc964d4' 
  AND token = 'w71Ostxs0k+eGwbG3NUERuJ/OENm0HQlFzQ+Gi4IYGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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