SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '82637b06685d93c4b3988bb4abae72df3e0888186f528ed9915a6b425904e770' 
  AND token = 'cshFPqTcevOMbGZQY+Uafgn6rGymVN7jHsochSEaTi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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