SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92650aecb104d9dc48ecbcf6b1a9b21d746dfe80e379f01696658b2992314190' 
  AND token = '11uGzVwP9z30bCW5Vvr0dHWFhrJxzJ+bKspmLQ/Jmlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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