SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '828f9a4c6f8e2277e16e33a85a6cc282fe798038c9c68896b812862602b5b25f' 
  AND token = 'FH6sYCCXGqBBVx4Pi9aDBaJgR4LuzmxBjKSwZcoVsdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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