SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6796197c2015dc4af1afc1ffdc11abf6526a6a252481030b94662ab58f728217' 
  AND token = 'QKMphkSL0lNE2iqeSIxTFVC5AqX6DyXvzvckxGSnc0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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