SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fdb38f0cb617fc295b4cca421aa26b238312227bd2fe36497513ef578c06427' 
  AND token = 'J1ktxwRVVtxNDEj6X8syEd6/BO5rzoVFoXh/fstmsqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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