SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7f17b552ac296f2a1b7f8180deb72e5cd077ca1ad903c0adf5a88667613e4833' 
  AND token = 'G0NuVVuEbMQtCcQzs9hJNow0wa3w9qhvDMbwznm/ZSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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