SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4962eade618b6fa11e5fc385f75c56941e3afe199b94c98a25d4f3ba730c15d' 
  AND token = 'ezUpTILadIDwKO0ZY6/B5wffPxnFzOFXVUe+DgY+fXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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