SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6e0388b024494a912e70e66ebbaf06c5ffc06caaaa7cae6b5cce4bc295a10d1' 
  AND token = 'qcSsBFWS/k7kCMtqaxCXGWau0By3LeJo+OrpEqqeXdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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