SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b53e2196024355c8385da7ff13e9b5c98f644c56cff398c43972ed337d378a9' 
  AND token = 'SeWhKIcgLtjwxBwdNdjc/5OtrQh8uB9k/DVwWROpbmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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