SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24ffa646b259e7e30b6805a782b375ee7451946f46c359584cf753e7571866ea' 
  AND token = 'hjG7wfOUoVs1giFK1h9FoOpukpQK8CUhw1p1QvaArJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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