SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dcf490ddbe3ed24689086a341f7490d995437827d383a9439605f590ff1641e' 
  AND token = 'yxO4JtmH1PjCaBKVgbS7P6s3WhDDUN+xGxRq+cl3B10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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