SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47aa03e27f4585371cb2d7bdbcb3971b21e1ab8195b6f3ad4621012947a2e306' 
  AND token = 'ldL/UtnPfgUMRG6onx2JHi2vpMOs3CJJQHJJIO955TA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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