SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '644463510c187b8ff920b9b685a36c49945c60dba5c7d804ea1235c987a44dd2' 
  AND token = 'Y8/RqGksb93ZXAq2bhQOesFpiQSznpYVk93AFBHhDEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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