SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38facf21637a5b1e6489d2429f08fda33bb8a8070157ee8625f345ca0c3a17f2' 
  AND token = 'A2x0yc1f15XxfO778Plr2fhGOa12El5XHWkYqli53pw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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