SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e632162f1b64414744c3720d403b6baaa94294acba5852bf2db1632c6133f58f' 
  AND token = '8qrY4zSgWKfFyrwmEYDeWGpQA/fFhzmjFsZ8o7bNLew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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