SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df40b7058cdd010ae355a51df02864a95cdfeb99546a92d3d54dde01aa26dc21' 
  AND token = 'tje9VUR6oryISrgyKOOiqtBK5lcN46FLt/o6wpLaQAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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