SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c9bbc20f3296557f618be331e0f48c021063a2d0304dcc072dc1c0a3a1b5816' 
  AND token = 'pm5O/iVwFAEqdplSQd+0tL2sl1qgW4DWo1ztF8pidDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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