SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bc059627e5a08b863cb15de60f81606bceae1e5b78be5a281b576a86e17969b' 
  AND token = 'E2kBZdNan6onjunRjvdklKshyLWxFCiKNdbnBGe3pqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}