SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1abfbbcf1eaabd081e5397eab963f6ec79a41a139d40c2f12df0b077e86035e0' 
  AND token = 'WyGzYHuraoe2KHTfAE8gUKBbeGdkTkvlrtFxS5TjAeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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