SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffbbfac233b1d7b310a92fc7352e4769936f1265146248be343884522965bd6f' 
  AND token = 'VJcVPwpsPmnk5eKB/Q+5zKuNx9KOBj5yPSgStZrcsN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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