SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6920685f7361a4690c6d0b7c63815733b7c55dfb6c18256b1f0a0a9eec841f0a' 
  AND token = 'K7U2TUOCBpmXwNzRGoq85tDuxxWQFIl8Q57zvCZSxes=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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