SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8ab043f32772fad853d242a244a8fe598d1558f06cd1e108f948e359ff2f9f3' 
  AND token = 'zVcHQkvgJjwR6T/Bfgb/j9mLRAHNYToIGFmjQ2lb8w4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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