SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae7b030c661960828967d0f2ed81f55bafa792ec485d4cf4b717be4d9369881f' 
  AND token = 'YY5wReJLCW36hy8SUFBS06LMdQxn2VTsiwQDTGYE1zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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