SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dd15324b79a9b4077b16924391dc75890c1d85b1858e4b2cec3ae92fb71179d' 
  AND token = 'ynUXJanZqXGJ/4tJYczmtzjjCxUMFdTEphaAJqNTz7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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