SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fd15286af0bb6e08be2d88f49efcdc542ea144f33820001477ecf27fb5a394c6' 
  AND token = 'uV/ehS6TDh0eIM4gS+CDv/V/UCJ+g/cjmCEYMIg1hqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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