SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56fd050e30eacee6c3a090a7119b4bfe0a1049b34ba365c40f4615eb51f3bbb5' 
  AND token = '3ohHW+4QTvq3RIl3H0nQnb7fi8Oyu4xxKGoRPYgBWQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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