SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdf844d8772e1371d06e48898a89411eac48e722afc6b9acd3bd9954acf52e84' 
  AND token = 'ABB2Swtsahbe/zEGbhRfuOkYPT5FzDnkyyQUWNRbgeU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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