SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '492fdb349ed5b2434414e7aab201285005db4dd9b6ae63a46097885d605ecda3' 
  AND token = 'hM+l8Uu7vfIlaaGfESsMAnQa7lkHyT+jXJ/u2z2I0zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}