SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11d5fd7d2b6c9bc2c198529df068887b5fbc9864049f63097bd12a2b5baa4396' 
  AND token = '+Beagbzqh7Cu1Gb3z6W97wSiDYh9IkrnBI+uiUJ8C/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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