SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7790466d79b12b29e62a701b548c8301b6b3caad0ecf5a3e008d35976ef57b6' 
  AND token = 'pQYWjGWuI4ElmtycwPnmasvYg+x7qtH9/JA5QuBqLTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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