SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3a09ceeb91679449ca455cfa1170deb2f3835711a77f04e3ff24faf6f2cb384' 
  AND token = 'CLhHBW+zX2fVKpDOTUvI4cxN9SLkkaBxNv8XikQWUvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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