SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa54a31a41e88d02de1ab4dac59128b177508f3431dc34f2320dcabf02a3b0d8' 
  AND token = 'bHtD6rMnfsOf76r0jJvWSNlFUkyi/VhgazfFtx19KlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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