SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0015e68ec1aa6534cb061e75ab7dfa98df2698ad237ae505f86856549cab0a55' 
  AND token = 'ErtZzHvwxOKUtD3xjSoOWOC7ppADm211MdgAFNuPtnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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