SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cae68ef74581682ffc3e9e028e0d4ad609a61b8286a030b04df2c229325ed30' 
  AND token = 'Zp40wQDaja+WHc5jD1PDs27L2RdWOacxqKaRd5ZPu/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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