SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '607f2219f4ca60b67d1404ea29001c23179e62b40a1a345f09422091b16db250' 
  AND token = 'XfFXgj3Y5m2NmOJU4x6tIQfI/ehTPTT3ratXG9VWCf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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