SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b9e148c895192219e08dfd23bf7630935e9fc49520cb19d6e685b0c4931d66c' 
  AND token = 'sfr23mFMVC6avbFm9uj8wHZMWxJcLPwALrfXZ2Lo3+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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