SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '570402495ee7050798efed309a4de20785de0c9ecac375f47482a6ef5a41cece' 
  AND token = 'lqmtZVLFcjukqYJkO0J2g1KBLrXaXsnv6BiZMxO1stU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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