SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd296bbba21179f9bfb0309e0cbaf679a2916170f95b915cff05e5d57e2e8670e' 
  AND token = 'hMqz+ocA3rZFl9mcYptfBK4jGcZ3qtfYmkulLo9LMng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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