SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb0ff6524722655623e788caf66105c1393ef8e213170890d096ffae1e1dc9ab' 
  AND token = 'RWajbHZkSU5Sfx7hnQPRm44AlGfgNM/XbuziCplEjtQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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