SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e414faaec6d7b8bb39946e975ae153aec6fb0fbd33d5db185573f3200777b29' 
  AND token = 'nnCPT2ZtNcBnRdUpeSptUmrVwsAEvXhcYuPnLr8LEc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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