SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f352c2b29a552a9f987c615988df41a2149b3070cc71a893d383d8512f98ddf8' 
  AND token = 'ySPMztgcWUf2Z3bkEXvBkoop18IYoLkuH+tPAxXwIzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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