SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5eebc0bfb2020988f9133e5593fbf96a65fc14e7f892d580c14a5b941b590517' 
  AND token = 'pewUlTUEWi/+DaUgqya78GubwO/ckYjka74Db0WXh4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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