SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b6fbef22b2a8cc1c00f5d985fadf7900523bcec9ea17eb6a76bbad607ffa1a6e' 
  AND token = 'mYs1jE2RBUcVdkyk85xsGzR9Wz13h6CKCAcG/sOFKjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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