SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebfc0d6d80839701188ba7cd601302779888acb39272c914909917cf80001668' 
  AND token = 'wGj6ztjMKPRtZ+wf/vkt8B2ITZGP80M0bnOVbEnD/lk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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