SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b954312992d474eafd71233aace4632111ede90d6ab6f0c24a88238bcd75ab1e' 
  AND token = '9PUIgbPxLhOa/hdV0efXH5Ia+HkUpe2DU139Yiz18nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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