SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7b4f7b942baf5e4135137fb3271584dfbc14fb9993b69a71060d7780f6e90717' 
  AND token = '1EFgS946A50918FBs0fOsWp2kPUTrO5OcY5QX6qQmL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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