SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a10ea0440820afae40005a04234073d33a5045d46c883dd5c6d5cab736496d67' 
  AND token = 'kfKpPoBxh4iIzadGq0OhVRX/UWF2mqtaCmpDML22+4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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