SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74df33842a3ce3d0e06bb16d8b622403618bc420043a527d00aca75b1a965a6f' 
  AND token = 'Gw+sHA4zAcUa93DMQQhOJqJ6DgOpFlbZjgjAlSzCupQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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