SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73d8203952fb724c505ca0cee77045ca6a282b10a742c1b0d7badaea2f210bf4' 
  AND token = 'teq43YkgOd0vLiWlAtPvMIJrRcyLNIDjty02V3zxVoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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