SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba9c9289841100b5116413096af19de73fb76723a370e1ad81a600aa707f3aa5' 
  AND token = 'Nizm7KMbdeYqyodwxm8ghA0M5Q7jxe/5/QxSSjryZzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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