SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '014bf9e3916ecbf749cd111a57fc541d4f908275103793fd0a7a7957d8359512' 
  AND token = 'FQYAxv7YX+WL4LBarfV8ohxAKFYWRRk8/xgmpVEgKko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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