SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69fddff0c41d563f982d31a94974b500421066ff3f9ea3c547f6e14801b99810' 
  AND token = 'tWoq4mNmW+flrf+/hU/n3o/RTReBLXxdfh1ld2Ta3nQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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