SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd18126ddfccad969f613f27e003574097a9f3c02d1ca73fccb091aa7dfae890d' 
  AND token = 'oEIlJcNY6CSxL4ZwNeL0HsBYpsOJPIOvbj5snCl6v/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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