SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3fd76bc9c7e84546a16a149f066be3b44accbed6f9d5a594451d544218e743bb' 
  AND token = 'U/E1YgYoOGDDGm/VHAVbB3aTnbCXUK2UMCpHknhqkG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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