SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe402473aa91127989c5c89ed3d95cad0d51b717334d523f5a067025615f8a83' 
  AND token = 'zDPdWGc5SjLO9Zl/ZW6tClz/ZThilGu9BCJwSfuUCcE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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