SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d073c0a48263f9cf82700f04ce098e3aee97551caea8c23e18e94ecbd882d31' 
  AND token = 'mTZLnbR6IuiUGwNdzxNx1T+16v6cYaJt8wFPWzLD+Tw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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