SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07612c108c41fe6a9f5079b8228e8baac73bcd2a7c7cfecf9bbeabba735e628a' 
  AND token = 'd36pBj+xh0xK91U2QlR19WsrJaYKACISHIwrjDMeqIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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